Longevity of routes in mobile ad hoc networks

An ad hoc network is a collection of mobile nodes where communication takes place through the wireless medium and in the absence of any fixed infrastructure. Direct communication is only possible between neighboring nodes and hence multi hop communication becomes necessary for distant nodes. It is essential that a routing protocol is used by a source node to discover a route to the destination node so that it can successfully transmit its message via the intermediate nodes. The lifetime of a particular route is dependent on the speed and direction of movement of all the nodes involved in the route. In this paper, we investigate the expected lifetime of a route so that the route discovery protocol can be invoked at the right time without disrupting the communication. We argue that if the movement pattern of the nodes is absolutely deterministic then the lifetime of a route can be determined exactly. On the other hand, a chaotic mobility pattern will bring in uncertainty to the lifetime of the route. We calculate the expected lifetime for different mobility models